Ants

Ants and Plants Gallery

spinicola6s.jpg

Common caricatures of Darwinian evolution evoke nature as a brutal force, one of ruthless competition in which the strongest prevail. In truth evolutionary processes can be much more nuanced. Under a wide array of conditions, species find Darwinian advantage in cooperative relationships.

Some of the most striking cases of evolutionary partnerships involve the planet’s dominant primary producers, the plants, and the most abundant insects, the ants. Ants are exceptional predators, and several groups of plants have figured out that by housing and feeding resident ant colonies they gain a potent defensive shield against their herbivores and other plant competitors. Ant-Plant associations are apparently beneficial enough for both parties that highly-specialized obligatory relationships have evolved many times.

Why do I bring this up? Because I’ve just posted a new Ants and Plants gallery:

http://www.alexanderwild.com/gallery/4001891

At the moment the gallery contains images of just three such systems: the Neotropical AcaciaPseudomyrmex and Cecropia-Azteca systems and the Australian Myrmecodia-Philidris partnership. These are just a few of the ant-plant systems that exist, though, there are more equally photogenic ones that I’ve not yet had the luck to photograph.

Public Service Announcement: Formica nitidiventris = F. pallidefulva

Formica incerta

In the comments, James Trager brings to our attention his recent synonymy of the venerable Formica nitidiventris with Formica pallidefulva. This is one of the most common ants, and in my opinion one of the prettiest, in eastern North America. Many of us from the east learned of this ubiquitous species incorrectly as F. nitidiventris, so the synonymy may take some getting used to. In any case, the name nitidiventris is sunk, so you’ll only make yourself look obsolete if you persist in using it.

The Trager et al (2007) revision of the Formica pallidefulva group is excellent, by the way. Thorough and well-illustrated. I had no troubles sorting out the ants in my collection, which turned out to contain all five of the group’s species.

source: Trager, J. C., J. A. MacGown and M. D. Trager. 2007. Revision of the Nearctic endemic Formica pallidefulva group, pp 610-636. In Snelling, R. R., B. L. Fisher, and P. S. Ward (eds) Advances in ant systematics (Hymenoptera: Formicidae): homage to E. O. Wilson – 50 years of contributions. Memoirs of the American Entomological Institute, 80.

Need Money Fast?

Apparently, there are people on the internet willing to pay you to not kill the ants in your yard. The site “Adopt an Ant” explains:

Well my name is Tony and I have recently moved into my new home.

After moving in I have seen there is a large ants nest at the bottom of my garden. In this ants nest there are 1 million ants living there.

All the ants are happy go lucky ants with there own Unique personality,

The problem is the plan was to flag my back garden and this would destroy the nest and all the ants.

To save these Ants from DEATH please adopt an ant TODAY.

the money raised will go to preserving the nest of 1 million ants and making my garden ant friendly, there for saving the ants from certain DEATH.

It’s a brilliant idea. I’ve got a harvester ant nest out back that I could hold hostage for cash, but I suspect I’d make more money by refraining from drowning our neighborhood’s many feral cats. For just $10 an adopted kitty, you too can save a life.

2007: The Year in Ants

invictafight13s.jpg

This week the blogosphere is busy recapping 2007 with lists of top stories in politics, news, and celebrity haircuts. In all the hoopla surrounding year’s end, somehow everyone seems to have forgotten the ants, even though the, um, fast-paced world of Myrmecology has made plenty of discoveries this year. In no particular order, here is my list of the most significant advances in Ant Science from 2007. (more…)

Photo Technique: Post-Processing

Photos posted to myrmecos.net rarely go straight from the camera to the web. Through some combination of errors related to exposure and the innate properties of digital sensors, raw images can be a surprisingly poor match to what is seen through the viewfinder. Raw images are often relatively flat in appearance, with colors that are shifted or off-hue. For instance, Canon cameras by default impart a warm reddish hue to their files that is especially apparent in macrophotography. The nice thing about raw files, and indeed the main reason for using them, is that they are malleable enough to allow a wide latitude of corrections.

How much do I alter the raw images? You can see for yourself. Here I’ve posted a series of before/after comparisons (raw and uncropped above, processed below). Click on each to enlarge.

comp6.jpg crop7.jpg pp11a.jpg

comp11.jpg comp2.jpg comp3.jpg

If an original image is within reasonable boundaries of exposure and composition, and it was taken using the camera’s raw settings (not jpeg!), they can be adjusted to more closely match what I remember seeing in the viewfinder. Below is an example. (more…)

The Ants of Paraguay

Camponotus personatus

Paraguay may be the world’s most important country. Never mind that it is economically isolated and geopolitically forgettable. Rather, I measure importance by less trivial metrics, and by that of course I mean ants.

Paraguayan ants have changed the world. Many of the world’s worst pest species evolved on the broad plains of the Paraná river before hitchhiking with human commerce to points abroad. The infamous fire ants in the southern U.S. originated on the Paraná, as did the Argentine Ants that plague California and Europe, along with a rogue’s gallery of other trampy and invasive species. These invasives transform ecosystems and drive native species to extinction. Not to mention that some of them are champion stingers and are very good at getting into houses, greenhouses, and wherever else they can stir up trouble.

We do not know why ants from this region are so potent, but perhaps something about the Paraná acts as a cradle for pestilence. Sadly, we’re a pretty long way from finding out, as the ant fauna in that part of the world has been among the most poorly-documented anywhere. We know a fair bit about what happens to these ants after they arrive in Europe, Hawaii, Florida, and other places frequented by scientists, but what goes on in the native range is largely a black box. I’ve been slowly been chipping away at the problem by cataloging the ant species that live in Paraguay. You can check out the progress- accompanied by April Nobile’s amazing ant images- here:

The Ants of Paraguay

casent0173706_h_1_med.jpg

 

For more details, the full catalog is here (full text is subscription only, sorry):

Wild, A. L. 2007. A Catalogue of the Ants of Paraguay (Hymenoptera: Formicidae). Zootaxa 1622: 1-55.

The Current State of Ant Taxonomy…

…reviewed by Phil Ward here:

Ward, P.S. 2007. Phylogeny, classification, and species-level taxonomy of ants (Hymenoptera: Formicidae). Zootaxa 1668: 549-563.

Abstract: The current state of ant systematics is reviewed. In recent years substantial progress has been made in identifying the major clades of ants and the relationships among them. Earlier inferences about ant phylogeny based on morphology have been refined and modified as a result of a recent influx of molecular (DNA sequence) data and new fossil discoveries. It is now apparent that much of the biological and taxonomic diversity of ants is contained within the “formicoid clade” which comprises 14 of the 20 extant subfamilies and about 90% of all species. Whether the remaining groups of extant ants (Leptanillinae and the poneroid subfamilies) represent a clade or a grade at the base of the ant tree remains unresolved. The fossil record for crown group ants extends back to 90–100 mya. Stem ants (sphecomyrmines, armaniines) were also present during this period. Molecular divergence date estimates that take into account the fossil record of both ants and other Hymenoptera suggest that crown group ants arose ~115–135 mya. Most of the extant ant subfamilies and genera are well defined morphologically and likely monophyletic, but there are some notable exceptions including the subfamily Cerapachyinae and several large and ambiguously delimited genera such as Pachycondyla. Several tribes in the large subfamilies Formicinae and Myrmicinae also represent artificial assemblages. Finally, while the specieslevel taxonomy of some ant genera is in a satisfactory state, taxonomic anarchy reigns in others, with numerous illdefined species and many names of uncertain applicability. Progress in this area of ant systematics will require sustained individual efforts, expansion of job opportunities, enlistment of new technologies, and a deeper understanding of the nature of ant species and the differences between them.

New Species: Trachymyrmex pomonae

pp10a.jpg
Trachymyrmex pomonae Rabeling & Cover 2007
Arizona
Nothing warms the heart more than a new ant species close to home! An all-star team of ant specialists, headed by Christian Rabeling at the University of Texas, describe the Arizonan species Trachymyrmex pomonae in Zootaxa this week. This spiny little red insect is part of a New World evolutionary radiation of agricultural ants, the attines, that cultivate a fungus in underground chambers. Trachymyrmex pomonae is one of several Trachymyrmex species in the United States, with dozens more occurring in Central and South America.

New species discovery is not so simple as finding a critter in the woods and declaring “Eureka!” A background knowledge of related species is essential for recognizing something novel. Trachymyrmex has been an especially challenging group of ants in this regard, as the published taxonomy of the group is limited and many of the species are confusingly similar. In the absence of a taxonomic synthesis, one is reduced to using isolated taxonomic papers written decades ago on individual species and going through endless drawers of museum specimens. Fortunately, Rabeling et al. do exactly that for the North American Trachymyrmex, and on top of it they throw in DNA sequence data from two loci sampled across multiple populations per species. Once the dust settled, they inferred the existence of nine species but had only eight valid, pre-existing names to apply to them. The extra species became the new T. pomonae.

Students of the biannual Ant Course in Arizona might recognize T. pomonae. It is not an uncommon ant around the Southwestern Research Station in Portal where the course is taught. If you’re an Arizona Ant Course alumnus, check your collection!

traspa1.jpg
Source: Rabeling, C., Cover, S. P., Johnson, R.A., and Mueller, U.G. 2007. A review of the North American species of the fungus-gardening ant genus Trachymyrmex (Hymenoptera: Formicidae). Zootaxa 1664: 1-53.